Many philosophers endorse a truth-insensitivity hypothesis: certain core, philosophically important evaluative properties of a belief are insensitive to whether it is true. For example, if two possible agents believe the same proposition for the same reason, then either both are justified or neither is. This does not change if it turns out that only one of the two agents has a true belief. Epitomizing this line of thought are thought experiments about radically deceived “brains in vats.”Proponents claim that the truth-insensitivity hypothesis is extremely intuitive and appealing pre-theoretically — we have an “overpowering inclination” to think that it’s true (Richard Fumerton). To deny the truth-insensitivity hypothesis has been labelled “extraordinary” and “dissident” (Earl Conee). However, other philosophers claim that exactly the opposite is true: the truth-insensitivity hypothesis itself is counterintuitive and violates commonsense. The appeal of truth-insensitive epistemology,. . .